/**
 * Accessibility Styles for OldWeb.tech
 * WCAG 2.1 Level AA compliant styles
 * Includes: skip links, screen reader utilities, focus indicators, high contrast support
 */

/* ============================================
   Screen Reader Only Content
   ============================================ */

/**
 * Hide content visually but keep it accessible to screen readers
 * Used for: live regions, additional context, skip links when not focused
 */
.sr-only {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border-width: 0 !important;
}

/**
 * Allow .sr-only content to be focusable when accessed via keyboard
 * Used for: skip links
 */
.sr-only-focusable:focus,
.sr-only-focusable:active {
  position: static !important;
  width: auto !important;
  height: auto !important;
  overflow: visible !important;
  clip: auto !important;
  white-space: normal !important;
}

/* ============================================
   Skip Links
   ============================================ */

/**
 * Skip to main content link
 * Hidden by default, appears on focus at top of page
 */
.skip-link {
  position: absolute;
  top: -100px;
  left: 0;
  z-index: 10000;
  padding: 12px 24px;
  background: #4fc3f7;
  color: #1a1a2e;
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: 0 0 4px 0;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 0;
  outline: 3px solid #fff;
  outline-offset: 2px;
}

.skip-link:hover {
  background: #81d4fa;
  color: #1a1a2e;
}

/* ============================================
   Enhanced Focus Indicators
   ============================================ */

/**
 * Remove default outline for mouse users while preserving for keyboard
 * Uses :focus-visible for better UX
 */
*:focus {
  outline: none;
}

/**
 * Enhanced focus indicator for keyboard navigation
 * WCAG 2.4.7 Focus Visible - Level AA
 * Minimum 2px, high contrast color
 */
*:focus-visible {
  outline: 3px solid #4fc3f7;
  outline-offset: 2px;
}

/**
 * Focus styles for interactive elements on dark background
 */
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
a:focus-visible {
  outline: 3px solid #4fc3f7;
  outline-offset: 2px;
  box-shadow: 0 0 0 4px rgba(79, 195, 247, 0.2);
}

/**
 * Focus styles for navigation elements
 */
.nav-category-btn:focus-visible,
.nav-dropdown a:focus-visible {
  outline: 3px solid #4fc3f7;
  outline-offset: 2px;
}

/* ============================================
   Form Error Handling
   ============================================ */

/**
 * Error message styling
 * role="alert" for immediate announcement
 */
.error-message {
  display: block;
  color: #ff5252;
  font-size: 0.875rem;
  margin-top: 4px;
  padding: 4px 8px;
  background: rgba(244, 67, 54, 0.1);
  border-left: 3px solid #ff5252;
  border-radius: 2px;
}

/**
 * Error state for inputs
 * Combines color, border, and icon for non-color-dependent indication
 */
input.error,
select.error,
textarea.error {
  border-color: #ff5252 !important;
  background-color: rgba(244, 67, 54, 0.05);
  box-shadow: 0 0 0 1px rgba(244, 67, 54, 0.2);
}

/**
 * Add visual error indicator icon (using CSS)
 */
input.error::after {
  content: ' ⚠';
  color: #ff5252;
  font-weight: bold;
}

/* ============================================
   Loading and Busy States
   ============================================ */

/**
 * Busy state for elements during async operations
 * aria-busy="true"
 */
[aria-busy="true"] {
  opacity: 0.6;
  cursor: wait;
  pointer-events: none;
}

[aria-busy="true"]::after {
  content: '...';
  animation: ellipsis 1.5s infinite;
}

@keyframes ellipsis {
  0%, 20% { content: '.'; }
  40% { content: '..'; }
  60%, 100% { content: '...'; }
}

/* ============================================
   High Contrast Mode Support
   ============================================ */

/**
 * Enhanced contrast for users with prefers-contrast: high
 * WCAG 1.4.3 Contrast (Minimum) - Level AA
 */
@media (prefers-contrast: high) {
  :root {
    --color-text: #ffffff;
    --color-text-secondary: #ffffff;
    --color-border: #ffffff;
  }

  .skip-link {
    background: #ffffff;
    color: #000000;
    border: 3px solid #000000;
  }

  *:focus-visible {
    outline: 4px solid #ffffff;
    outline-offset: 3px;
  }

  .error-message {
    background: #ff0000;
    color: #ffffff;
  }
}

/* ============================================
   Reduced Motion Support
   ============================================ */

/**
 * Respect user preference for reduced motion
 * WCAG 2.3.3 Animation from Interactions - Level AAA
 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .skip-link {
    transition: none;
  }
}

/* ============================================
   ARIA Live Region Visibility
   ============================================ */

/**
 * Ensure live regions are accessible but not visible
 */
#a11y-live-region {
  /* Will use .sr-only class from JavaScript */
}

/* ============================================
   Touch Target Sizing (Mobile)
   ============================================ */

/**
 * Ensure minimum 44x44px touch targets on mobile
 * WCAG 2.5.5 Target Size - Level AAA (recommended for mobile)
 */
@media (max-width: 768px) {
  button,
  a,
  input[type="button"],
  input[type="submit"],
  input[type="reset"],
  .copy-btn,
  .mask-btn,
  .nav-category-btn {
    min-height: 44px;
    min-width: 44px;
    padding: 12px 16px;
  }

  /* Ensure spacing between interactive elements */
  button + button,
  .mask-btn + .mask-btn {
    margin-left: 8px;
  }

  /* Input fields should be easily tappable */
  input[type="text"],
  input[type="number"],
  input[type="email"],
  input[type="password"],
  input[type="url"],
  select,
  textarea {
    min-height: 44px;
    padding: 12px;
    font-size: 16px; /* Prevents zoom on iOS */
  }
}

/* ============================================
   Required Field Indicators
   ============================================ */

/**
 * Visual indicator for required fields
 * Combines with aria-required="true"
 */
[aria-required="true"]::after,
.required::after {
  content: ' *';
  color: #ff5252;
  font-weight: bold;
  margin-left: 4px;
}

/* For labels associated with required inputs */
label:has(+ [aria-required="true"])::after,
label.required::after {
  content: ' *';
  color: #ff5252;
  font-weight: bold;
}

/* ============================================
   Disabled State
   ============================================ */

/**
 * Clear disabled state styling
 * Ensures 4.5:1 contrast ratio even for disabled elements
 */
button:disabled,
input:disabled,
select:disabled,
textarea:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  background-color: rgba(255, 255, 255, 0.1);
}

[aria-disabled="true"] {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* ============================================
   Landmark Role Enhancements
   ============================================ */

/**
 * Ensure main content area is clearly defined
 */
main,
[role="main"] {
  display: block;
  position: relative;
}

/**
 * Skip to content target styling
 * Makes focus visible when skip link is used
 */
main:focus,
[role="main"]:focus {
  outline: none; /* Remove focus ring */
}

main:focus::before,
[role="main"]:focus::before {
  content: '';
  position: absolute;
  top: -4px;
  left: -4px;
  right: -4px;
  bottom: -4px;
  border: 3px solid #4fc3f7;
  border-radius: 4px;
  pointer-events: none;
}

/* ============================================
   Custom Checkbox/Radio Accessibility
   ============================================ */

/**
 * Ensure custom controls maintain keyboard focus indicators
 */
input[type="checkbox"]:focus-visible + label,
input[type="radio"]:focus-visible + label {
  outline: 3px solid #4fc3f7;
  outline-offset: 2px;
}

/* ============================================
   Utility Classes
   ============================================ */

/**
 * Force focus visibility (for debugging)
 */
.force-focus-visible:focus {
  outline: 3px solid #ff0000 !important;
  outline-offset: 2px !important;
}

/**
 * Accessible hidden (display:none but preserves semantics)
 */
.a11y-hidden {
  display: none !important;
}

[aria-hidden="true"] {
  /* Already hidden from assistive tech, no additional styles needed */
}

/* ============================================
   Print Styles
   ============================================ */

@media print {
  .skip-link,
  #a11y-live-region {
    display: none !important;
  }
}